Unix Basics

Unix Accounts

One must have an “account” to use a Unix computer.– To share resources, need to tell users apart.

Username (public) and password (private).

You can only access the resources that are specified by your account information.– Accounts track, control, and limit user activity.

There is at least one super user account in a system usually named “root”, who has absolute power over the system. (On Microsoft Windows NT/2000/XP, this account is usually named“administrator”.)

Login to Your Account

Cursor

Prompt

User name

Password is not displayed.

Greetings from Unix.

After Login

Change password immediately after you login for the first time!

Ready for new command

Command

Login to Your Account from Home

Most Unix computers support remote login.–Unless it is deliberately turned off.

–ssh or telnet protocol.

You need– Internet access

–A ssh or telnet client program.ssh, slogin, telnet (unix, linux,

windows)putty (windows)

To Make a Good Password

A good password– Easily remembered by YOU

– Difficult to be guessed by others

Tricks to make a good password– Pick letters from a sentence

I love Unix Ioenx

– Pick letters, numbers, and symbols that sound, look like, or replace a phrase I hate carrots! ih8^s!

A bad password not only harms you– Attacks are much easier with a compromised

account on a computer

E-mail

mutt and pine are Unix utilities to read and send e-mail:

Forward email to another account of yours:– echo youraccount@yahoo.com >> .forward

Cancel the forwarding:– rm .forward

obelix > mutt obelix > pineor

Log out

When you’re done, don’t forget to logout!!!!!!!

obelix > exit

obelix > logout

Some Basic Commands

who: Who are using the system.obelix > who

moreno pts/1 Sep 7 14:08

li96 pts/2 Sep 7 14:29

obelix > who am i

moreno pts/1 Sep 7 14:08

who am i: Who am I.

Some Basic Commands

ls: List the files under current directory

obelix > ls

readme cs211.2.ppt cs211.ppt.gz notes.zip

cs211.1.ppt cs211.3.ppt make/ shell/

obelix > cat readme

Unix is easy!

obelix >

cat: Display the content of a file

Some Basic Commands 1

Ctrl-c: (press <Control> and c at the same time) Interrupt the current task.

obelix > cat

^c

obelix >

lynx: surf the net.

obelix > netscape

netscape or firefox: surf the net.

obelix > lynx www.google.ca

obelix > firefox

Some Basic Commands 2 man: See the manual page of a command.

xman: Graphical, X-Windows version

obelix > man cat

Reformatting page. Wait... Done

User Commands cat(1)

NAME cat - concatenate and display files

SYNOPSIS cat [ -nbsuvet ] [ file ... ]

DESCRIPTION

cat reads each file in sequence and writes it on the stan-

dard output. Thus:

example% cat file

prints file on your terminal, and:

example% cat file1 file2 >file3

concatenates file1 and file2, and writes the results in file3. ....

Exercise 1

telnet or ssh to your gaul account– telnet gaul.csd.uwo.ca

– user name: the same as your email account @uwo.ca

– initial password: your student id (with or without the leading zeros)

If you have no gaul account– The system group is waiting for the add/drop list of

the course

– Keep on trying everyday

Exercise 2

Try the Following Commands with man–cd: change directory to ..–more: show the content of a file in pages.–cp: copy a file from .. to ..– rm: remove a file. –mkdir: make a directory.– rmdir: remove a directory.–mv: move a file or directory to..

For now, do not remove or overwrite the files that are not created by yourself.

Exercise 3

Logout